[comp.sys.amiga.hardware] Motorola 68302

wayned@wddami.spoami.com (Wayne Diener) (10/10/90)

I went to a Motorola seminar last week and got a little interested
in a part called the 68302.  It has a 68000 core, a 32 bit (source
and destination) DMA, three timers, some parallel I/O lines, three
full duplex serial channels, 1152 bytes of on-board ram, DRAM refresh
counter, etc.  It comes in a 132 pin grid array and ceramic and plastic
flat packs.  Can run at 16.67 MHZ.

Anyway, it looked like it might be possible (with an adaptor board)
to fit this beast into a 68000 socket.  If it could be "fit" in,
could we end up with 500's, 1000's and vanilla 2000's with 4 serial channels,
and full DMA? (And I'm sure clever uses could be found for the timers
RAM, I/O, etc. also.)

If I had the time I might try it myself, but work and school take up

wayned@wddami.spoami.com (Wayne Diener) (10/15/90)

>In article <14767@netcom.UUCP> mcmahan@netcom.UUCP (Dave Mc Mahan) writes:
>
> In a previous article, wayned@wddami.spoami.com (Wayne Diener) writes:

>>I went to a Motorola seminar last week and got a little interested
>>in a part called the 68302.  It has a 68000 core, a 32 bit (source
>
>I have been using a variation of that chip (the 68332) at work, and wondered
>the same thing.  The biggest problem I can see with it is that it doesn't
>really have a true compatibility with the 68000.  The 332 (which I am most
>familiar with) is sort of a hybrid 68000/010/020 with a few extra things
>
>    -dave

Dont' let the similarity in the part numbers confuse you.  The 68302
is only _somewhat_ similar to the 68332 in that it also integrates
numerous peripheral functions on-board.  Ten feet away from me is
my 68332 evaluation board, and the manuals for both the 68302 and
the 68332 are scattered around here.  To quote from the Motorola
manual MC68302UM/AD REV 1:

In Section 1:

   'The MC68302 integrated multiprotocol processor (IMP) is ...
    first device to offer the benefits of a closely coupled,
    industry-standard M68000 micro-processor core and a flexible
    communications architecture.'

In Section 2:

   'Refer to the MC68000UM/AD, M680008-/16-/32-Bit Microprocessors
    User's Manual, for complete details of the on-chip microprocessor.'


DTACK ?  

In Section 5, Table 5-1, the bus control signals are listed as:

   ~AS, R/~W, ~UDS/A0, ~LDS/~DS, ~DTACK

As I said, it looks pretty 68000 compatible to me.   

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|       //                  Wayne D. Diener                     |
|      //                   Spokane, WA                         |
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mcmahan@netcom.UUCP (Dave Mc Mahan) (10/15/90)

 In a previous article, wayned@wddami.spoami.com (Wayne Diener) writes:
>I went to a Motorola seminar last week and got a little interested
>in a part called the 68302.  It has a 68000 core, a 32 bit (source
>and destination) DMA, three timers, some parallel I/O lines, three
>full duplex serial channels, 1152 bytes of on-board ram, DRAM refresh
>counter, etc.  It comes in a 132 pin grid array and ceramic and plastic
>flat packs.  Can run at 16.67 MHZ.
>
>Anyway, it looked like it might be possible (with an adaptor board)
>to fit this beast into a 68000 socket.  If it could be "fit" in,
>could we end up with 500's, 1000's and vanilla 2000's with 4 serial channels,
>and full DMA? (And I'm sure clever uses could be found for the timers
>RAM, I/O, etc. also.)

I have been using a variation of that chip (the 68332) at work, and wondered
the same thing.  The biggest problem I can see with it is that it doesn't
really have a true compatibility with the 68000.  The 332 (which I am most
familiar with) is sort of a hybrid 68000/010/020 with a few extra things
thrown in.  It has a few unique exceptions with new types of exception stack
frames.  It needs to be configured by special boot code for it to even start
running.  It has DSack0 and DSack1 instead of Dtack (like the 68000 does),
which can be solved, but is a pain.  You would have to figure out how to
get the E-clock to run synchronously if you ran at anything other than 7.15
MHz like the current amiga, and I think (but am not sure) that the E-clock
from the 332 is CPUClk/8, not CPUClk/10 like a normal 68000 product.  You
are quite correct in that it has some neat features (plus the fact that
it will be available soon in a 33 MHz version) but it would be a task to
fit it into the current system.  Who know, though?  With enough work, anything
will fit.


    -dave